Grenadin or something.

A work in progress that's been pretty fun to play so far. One of the strategies I like is Explosive Potential on Arach, Razorshaper, it lets you drop 5x Razorbots pretty easily. You can then sacrifice Arach, Razorshaper and get him back with Immortalize or the amplify on Nectar of Unlife for another 5x.

Rotoscavenger is another fun card, with Devour, Befoul, and Fearbinder you want to be sacrificing units anyway. I only have one Devious Drone otherwise I may add more; he's been extra fun to sacrifice.

I mostly added Nectar of Unlife and Vara's Favor to interact with Dark Purveyor, so I find myself holding them a lot. I like what Dark Purveyor's summon ability can do for Arach, Razorshaper as well.

Wretched Rats is a new card I haven't played with in the deck yet. I tossed out some other cards that weren't a great fit. I found I could use more life stealing and their Entomb is pretty great.

Vine Grafter and Wasteland Broker get us access to the market in our even only deck. I like both options, the +1/+1 goes well on Arach, Razorshaper too.